A semiconductor device, such as a semiconductor chip, may be attached to a substrate using flip-chip technology. In this process a series of connectors, such as solder balls, are formed on one side of the semiconductor chip, and then the semiconductor chip is “flipped” so that the solder balls are placed into contact with an underlying substrate. A reflow process is then performed to reflow the solder balls and form the necessary electrical connections between the semiconductor chip and the underlying substrate. An underfill material may then be applied between the semiconductor chip and the substrate in order to protect, both physically and chemically, the reflowed solder balls.
In some instances the underfill material not only encapsulates the region between the semiconductor chip and the substrate, but may also laterally extend away from the semiconductor chip to cover a larger area of the substrate than the semiconductor chip itself. As semiconductor chips are scaled down to smaller and smaller sizes, this extension of the underfill material becomes more critical, as this excess underfill material is needlessly taking up valuable area on the substrate
Furthermore, because the semiconductor chip is “flipped” over before it is placed onto the substrate, it is very difficult to accurately align the solder balls with their respective connections on the underlying substrate. Such an issue could lead to misalignments between the semiconductor chip and the substrate, and these misalignments could lead to unconnected power lines or missed signal lines, and at the worst, could cause a complete failure of communication between the semiconductor chip and the substrate.